In 1937, Aleksei A Borovkov and Ilya F Florov established
an experimental design bureau as OKB-7 with
the object of creating the smallest possible practical
single-seat fighter. The first prototype was completed
before the end of 1937, and was of heavily-staggered
cantilever biplane configuration with duraluminskinned
light alloy wings, a fuselage of mixed construction
(the forward portion being a duraluminskinned
welded steel-tube structure and the aft portion,
which included the cockpit, being a wooden
monocoque with plywood skinning) and wooden tail
surfaces. Power was provided by an 850hp Mikulin
M-85 14-cylinder radial. Favourable test results led to
two further refined prototypes being built as I-207s, these having Shvetsov M-62 and M-63 engines respectively
and each carrying an armament of four 7,62-mm
ShKAS machine guns. A pre-production series of four
I-207s was ordered in 1938, one being powered by the
1,100hp M-63 nine-cylinder radial, two having the
1,000hp M-62 nine-cylinder radial and the fourth
having a geared M-63R engine and a side-hingeing
cockpit canopy, all having retractable main undercarriages.
The I-207/M-63 attained a speed of 298 mph
(480 km/h) at 14,765 ft (4 500 m) during State Trials in
the summer of 1939, but the appearance of more
advanced fighters resulted in the 1-207 being discarded,
although both I-207/M62s were allegedly
employed operationally against the Finns during
1939-40.